(BIVN) – Hawaiian Electric is asking customers on Hawai‘i Island to reduce electricity use Tuesday evening, due to the unavailability or reduced output of several large generators.

The utility says the need to conserve power is especially important from 5 p.m. to 9 p.m., when electricity use is highest.

Brief rolling outages may be initiated in various areas around the entire island, the power company says, if another large generator were to unexpectedly trip offline.

From a Hawaiian Electric news release issued at just before 5 p.m. HST:

The request for conservation is prompted by the unavailability or reduced output of several large generators. Electricity on the island is generated by a combination of Hawaiian Electric facilities, independent producers who use wind, solar, geothermal and conventional generation to make power to sell to the utility, and about 17,000 rooftop solar systems.

Independent power producer Hamakua Energy unexpectedly tripped offline late this afternoon and Puna Geothermal Venture is operating at a reduced capacity. In addition, Hawaiian Electric’s Hill Plant Unit No. 5, Keahole CT-5, and Puna Steam Plant are unavailable due to planned annual maintenance or repairs. Wind resources, which help meet demand at night, also are forecast to be zero.

If another large generator were to unexpectedly trip offline or if wind and solar resources suddenly drop, brief rolling outages may be initiated in various areas around the entire island to prevent a loss of power to an even greater number of customers. The impacted areas and the timing of the outages are based on the amount of electric demand that needs to be reduced. Customers are asked to plan for outages lasting between 30 and 60 minutes. Updates will be posted on X (formerly Twitter) @HIElectricLight.

Suggestions for power conservation include “turning off air conditioners and unneeded lighting, shutting off water heaters and pumps, and delaying activities like cooking, showering, laundry, and dishwashing until late in the evening,” the company says.